Protein synthesis in heart muscle and the cardioprotective effect of μ-opioid receptor ligands at immobilization stress

Immobilization stress leads to the increase of ^99mTc-pyrophosphate accumulation in the heart that points to the cardiomyocyte damage. The stress-reaction was accompanied by a decrease of protein synthesis rate in the heart muscle and immunoreactive insulin level in blood plasma and increase of blood plasma cortisol and aldosteron. Pretreatment with agonists μ-opioid receptors DALDA and DAGO (0,1 mg/kg intraperitonealy (i.p.) twice during stress) completely prevented the stress-induction decrease of myocardial protein synthesis rate, heart damage and hormonal imbalance. Cycloheximide administration (0,3 mg/kg i.p.) increased rats myocardial membrane injury during immobilization and reduced cardioprotective effect of DALDA.